Probably because mind(s) will be changed as I go on. Its early days yet!
With everything in bits a course of action has to be decided on. Obviously its not in tablets of stone because (hopefully) as things progress and I develop an insight to the engine/receive advice from other sources, things may change.
The first thing to do is sort out the bottom end. All four main bearings need attention, as do the big ends. A full crank regrind and new white metal bearings seems like a good place to start. A good local company to me 'Paynes' can't cope with the size of crank - they sold their big grinder to 'Custom Cranks'. I got all of the dimensions together and spent an evening researching and emailing people.
The crankshaft dimensions are:
Overall length: 43.5"
Stroke: 6"
Main bearings: end (two off) 4.25"long x 2.375" diameter + intermediate (two off) 2.75 long x 2.375 diameter
Big end journals (3 off) 2.125" long x 2.375" diameter
and its damn heavy!
Let's see what the virtual postman comes up with.
The next question is the pistons. Sarah & Jim (Warrior) changed their original cast iron ones to alloy units. I want to try to keep as much of the engine as original as possible. Initial investigations have revealed that the ring grooves appear to be good. Lionel supplied a full set of replacement compression and scraper rings with the engine. If I keep the original pistons, I can use the original connecting rods and big end bearing housings. At this stage I'll keep an open mind.
One thing that does need sorting is the liners. All three have a lip at the top of the swept length. I've been told that the Russell Newbery liners are slightly different to the National ones. I need to talk to RN to ascertain what needs to be done to make them fit. Maybe this will drive the 'piston' scenario as well?
The other things to think about (even at this stage) is:
The gearbox/output arrangements. The current plan is to fit a prm style gear box. Probably with a 1.5:1 ratio throwing a fairly big prop - 24". The big question is which end to drive it from? A traditional arrangement with the flywheel at the bow end and of the engine and the gearbox at the back or a shaft off the the flywheel end to a gearbox. I will need to ponder both the engineering requirements and the the cost!
Speed control/governor arrangements. Currently the engine appears to have a vertical variable speed governor. How it works in practice I still need to understand. If anyone out there has any suggestions? Have a look at the photo links there's quite a few of the governor.
Engine cooling. Now here's one that always causes debate. I would like to keep the original plunger type circulating pump. This rules out skin tank cooling due to the coolant additives attacking the pump seals. That said, I've nothing against raw water cooling direct from the cut. There is always something very reassuring about seeing a spurt of water coming out of the side! If I go with skin tanks, I'll need a Jabsco and some way of driving it. mmmmm........
I think these are all questions I need to ponder over the Christmas/new year break.
3 comments:
Brilliant! A blog! Will give it a mention and put in a link. And follow it with great interest.
Nice decompression levers!! much better than ours. Will follow all with great interest. We will have to have some T-shirts made.
Jim
Very interesting reading. At what age did you decide to take on such a daunting project. At a guess you must be retired with plenty of time on your hands.
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